s3: smbd: Change filename_convert_smb1_search_path() to use extract_snapshot_token().

[Samba.git] / source3 / smbd / filename.c

/*
   Unix SMB/CIFS implementation.
   filename handling routines
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Jeremy Allison 1999-2007
   Copyright (C) Ying Chen 2000
   Copyright (C) Volker Lendecke 2007

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
 * New hash table stat cache code added by Ying Chen.
 */

#include "includes.h"
#include "system/filesys.h"
#include "fake_file.h"
#include "smbd/smbd.h"
#include "smbd/globals.h"
#include "lib/util/memcache.h"

static NTSTATUS get_real_filename(connection_struct *conn,
                                  struct smb_filename *path,
                                  const char *name,
                                  TALLOC_CTX *mem_ctx,
                                  char **found_name);

static NTSTATUS check_name(connection_struct *conn,
                           const struct smb_filename *smb_fname);

uint32_t ucf_flags_from_smb_request(struct smb_request *req)
{
        uint32_t ucf_flags = 0;

        if (req != NULL) {
                if (req->posix_pathnames) {
                        ucf_flags |= UCF_POSIX_PATHNAMES;
                }
                if (req->flags2 & FLAGS2_DFS_PATHNAMES) {
                        ucf_flags |= UCF_DFS_PATHNAME;
                }
                if (req->flags2 & FLAGS2_REPARSE_PATH) {
                        ucf_flags |= UCF_GMT_PATHNAME;
                }
        }

        return ucf_flags;
}

uint32_t filename_create_ucf_flags(struct smb_request *req, uint32_t create_disposition)
{
        uint32_t ucf_flags = 0;

        ucf_flags |= ucf_flags_from_smb_request(req);

        switch (create_disposition) {
        case FILE_OPEN:
        case FILE_OVERWRITE:
                break;
        case FILE_SUPERSEDE:
        case FILE_CREATE:
        case FILE_OPEN_IF:
        case FILE_OVERWRITE_IF:
                ucf_flags |= UCF_PREP_CREATEFILE;
                break;
        }

        return ucf_flags;
}

static NTSTATUS build_stream_path(TALLOC_CTX *mem_ctx,
                                  connection_struct *conn,
                                  struct smb_filename *smb_fname);

/****************************************************************************
 Mangle the 2nd name and check if it is then equal to the first name.
****************************************************************************/

static bool mangled_equal(const char *name1,
                        const char *name2,
                        const struct share_params *p)
{
        char mname[13];

        if (!name_to_8_3(name2, mname, False, p)) {
                return False;
        }
        return strequal(name1, mname);
}

static NTSTATUS check_for_dot_component(const struct smb_filename *smb_fname)
{
        /* Ensure we catch all names with in "/."
           this is disallowed under Windows and
           in POSIX they've already been removed. */
        const char *p = strstr(smb_fname->base_name, "/."); /*mb safe*/
        if (p) {
                if (p[2] == '/') {
                        /* Error code within a pathname. */
                        return NT_STATUS_OBJECT_PATH_NOT_FOUND;
                } else if (p[2] == '\0') {
                        /* Error code at the end of a pathname. */
                        return NT_STATUS_OBJECT_NAME_INVALID;
                }
        }
        return NT_STATUS_OK;
}

/****************************************************************************
 Optimization for common case where the missing part
 is in the last component and the client already
 sent the correct case.
 Returns NT_STATUS_OK to mean continue the tree walk
 (possibly with modified start pointer).
 Any other NT_STATUS_XXX error means terminate the path
 lookup here.
****************************************************************************/

static NTSTATUS check_parent_exists(TALLOC_CTX *ctx,
                                connection_struct *conn,
                                bool posix_pathnames,
                                const struct smb_filename *smb_fname,
                                char **pp_dirpath,
                                char **pp_start,
                                int *p_parent_stat_errno)
{
        char *parent_name = NULL;
        struct smb_filename *parent_fname = NULL;
        const char *last_component = NULL;
        NTSTATUS status;
        int ret;

        if (!parent_dirname(ctx, smb_fname->base_name,
                                &parent_name,
                                &last_component)) {
                return NT_STATUS_NO_MEMORY;
        }

        if (!posix_pathnames) {
                if (ms_has_wild(parent_name)) {
                        goto no_optimization_out;
                }
        }

        /*
         * If there was no parent component in
         * smb_fname->base_name then don't do this
         * optimization.
         */
        if (smb_fname->base_name == last_component) {
                goto no_optimization_out;
        }

        parent_fname = synthetic_smb_fname(ctx,
                                           parent_name,
                                           NULL,
                                           NULL,
                                           smb_fname->twrp,
                                           smb_fname->flags);
        if (parent_fname == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        ret = vfs_stat(conn, parent_fname);

        /* If the parent stat failed, just continue
           with the normal tree walk. */

        if (ret == -1) {
                /*
                 * Optimization. Preserving the
                 * errno from the STAT/LSTAT here
                 * will allow us to save a duplicate
                 * STAT/LSTAT system call of the parent
                 * pathname in a hot code path in the caller.
                 */
                if (p_parent_stat_errno != NULL) {
                        *p_parent_stat_errno = errno;
                }
                goto no_optimization_out;
        }

        status = check_for_dot_component(parent_fname);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        /* Parent exists - set "start" to be the
         * last component to shorten the tree walk. */

        /*
         * Safe to use discard_const_p
         * here as last_component points
         * into our smb_fname->base_name.
         */
        *pp_start = discard_const_p(char, last_component);

        /* Update dirpath. */
        TALLOC_FREE(*pp_dirpath);
        *pp_dirpath = talloc_strdup(ctx, parent_fname->base_name);
        if (!*pp_dirpath) {
                return NT_STATUS_NO_MEMORY;
        }

        DEBUG(5,("check_parent_exists: name "
                "= %s, dirpath = %s, "
                "start = %s\n",
                smb_fname->base_name,
                *pp_dirpath,
                *pp_start));

        return NT_STATUS_OK;

  no_optimization_out:

        /*
         * We must still return an *pp_dirpath
         * initialized to ".", and a *pp_start
         * pointing at smb_fname->base_name.
         */

        TALLOC_FREE(parent_name);
        TALLOC_FREE(parent_fname);

        *pp_dirpath = talloc_strdup(ctx, ".");
        if (*pp_dirpath == NULL) {
                return NT_STATUS_NO_MEMORY;
        }
        /*
         * Safe to use discard_const_p
         * here as by convention smb_fname->base_name
         * is allocated off ctx.
         */
        *pp_start = discard_const_p(char, smb_fname->base_name);
        return NT_STATUS_OK;
}

static bool find_snapshot_token(
        const char *filename,
        const char **_start,
        const char **_next_component,
        NTTIME *twrp)
{
        const char *start = NULL;
        const char *end = NULL;
        struct tm tm;
        time_t t;

        start = strstr_m(filename, "@GMT-");

        if (start == NULL) {
                return false;
        }

        if ((start > filename) && (start[-1] != '/')) {
                /* the GMT-token does not start a path-component */
                return false;
        }

        end = strptime(start, GMT_FORMAT, &tm);
        if (end == NULL) {
                /* Not a valid timestring. */
                return false;
        }

        if ((end[0] != '\0') && (end[0] != '/')) {
                /*
                 * It is not a complete path component, i.e. the path
                 * component continues after the gmt-token.
                 */
                return false;
        }

        tm.tm_isdst = -1;
        t = timegm(&tm);
        unix_to_nt_time(twrp, t);

        DBG_DEBUG("Extracted @GMT-Timestamp %s\n",
                  nt_time_string(talloc_tos(), *twrp));

        *_start = start;

        if (end[0] == '/') {
                end += 1;
        }
        *_next_component = end;

        return true;
}

bool extract_snapshot_token(char *fname, uint32_t ucf_flags, NTTIME *twrp)
{
        const char *start = NULL;
        const char *next = NULL;
        size_t remaining;
        bool found;
        bool posix_path = (ucf_flags & UCF_POSIX_PATHNAMES);
        bool msdfs_path = (ucf_flags & UCF_DFS_PATHNAME);

        if (msdfs_path && !posix_path) {
                /*
                 * A raw (non-POSIX) MSDFS path looks like \server\share\path.
                 * find_snapshot_token only looks for '/' separators.
                 * Convert the separator characters in place.
                 */
                string_replace(fname, '\\', '/');
        }
        found = find_snapshot_token(fname, &start, &next, twrp);
        if (msdfs_path && !posix_path) {
                /* Put the original separators back. */
                string_replace(fname, '/', '\\');
        }
        if (!found) {
                return false;
        }

        remaining = strlen(next);
        memmove(discard_const_p(char, start), next, remaining+1);

        return true;
}

/*
 * Strip a valid @GMT-token from any incoming filename path,
 * adding any NTTIME encoded in the pathname into the
 * twrp field of the passed in smb_fname.
 *
 * Valid @GMT-tokens look like @GMT-YYYY-MM-DD-HH-MM-SS
 * at the *start* of a pathname component.
 *
 * If twrp is passed in then smb_fname->twrp is set to that
 * value, and the @GMT-token part of the filename is removed
 * and does not change the stored smb_fname->twrp.
 *
 */

NTSTATUS canonicalize_snapshot_path(struct smb_filename *smb_fname,
                                    uint32_t ucf_flags,
                                    NTTIME twrp)
{
        bool found;

        if (twrp != 0) {
                smb_fname->twrp = twrp;
        }

        if (!(ucf_flags & UCF_GMT_PATHNAME)) {
                return NT_STATUS_OK;
        }

        found = extract_snapshot_token(smb_fname->base_name, ucf_flags, &twrp);
        if (!found) {
                return NT_STATUS_OK;
        }

        if (smb_fname->twrp == 0) {
                smb_fname->twrp = twrp;
        }

        return NT_STATUS_OK;
}

static bool strnorm(char *s, int case_default)
{
        if (case_default == CASE_UPPER)
                return strupper_m(s);
        else
                return strlower_m(s);
}

/*
 * Utility function to normalize case on an incoming client filename
 * if required on this connection struct.
 * Performs an in-place case conversion guaranteed to stay the same size.
 */

static NTSTATUS normalize_filename_case(connection_struct *conn,
                                        char *filename,
                                        uint32_t ucf_flags)
{
        bool ok;

        if (ucf_flags & UCF_POSIX_PATHNAMES) {
                /*
                 * POSIX never normalizes filename case.
                 */
                return NT_STATUS_OK;
        }
        if (!conn->case_sensitive) {
                return NT_STATUS_OK;
        }
        if (conn->case_preserve) {
                return NT_STATUS_OK;
        }
        if (conn->short_case_preserve) {
                return NT_STATUS_OK;
        }
        ok = strnorm(filename, lp_default_case(SNUM(conn)));
        if (!ok) {
                return NT_STATUS_INVALID_PARAMETER;
        }
        return NT_STATUS_OK;
}

/****************************************************************************
This routine is called to convert names from the dos namespace to unix
namespace. It needs to handle any case conversions, mangling, format changes,
streams etc.

We assume that we have already done a chdir() to the right "root" directory
for this service.

Conversion to basic unix format is already done in check_path_syntax().

Names must be relative to the root of the service - any leading /.  and
trailing /'s should have been trimmed by check_path_syntax().

The function will return an NTSTATUS error if some part of the name except for
the last part cannot be resolved, else NT_STATUS_OK.

Note NT_STATUS_OK doesn't mean the name exists or is valid, just that we
didn't get any fatal errors that should immediately terminate the calling SMB
processing whilst resolving.

If the orig_path was a stream, smb_filename->base_name will point to the base
filename, and smb_filename->stream_name will point to the stream name.  If
orig_path was not a stream, then smb_filename->stream_name will be NULL.

On exit from unix_convert, the smb_filename->st stat struct will be populated
if the file exists and was found, if not this stat struct will be filled with
zeros (and this can be detected by checking for nlinks = 0, which can never be
true for any file).
****************************************************************************/

struct uc_state {
        TALLOC_CTX *mem_ctx;
        struct connection_struct *conn;
        struct smb_filename *smb_fname;
        const char *orig_path;
        uint32_t ucf_flags;
        char *name;
        char *end;
        char *dirpath;
        char *stream;
        bool component_was_mangled;
        bool posix_pathnames;
        bool done;
        bool case_sensitive;
        bool case_preserve;
        bool short_case_preserve;
};

static NTSTATUS unix_convert_step_search_fail(
        struct uc_state *state, NTSTATUS status)
{
        char *unmangled;

        if (state->end) {
                /*
                 * An intermediate part of the name
                 * can't be found.
                 */
                DBG_DEBUG("Intermediate [%s] missing\n",
                          state->name);
                *state->end = '/';

                /*
                 * We need to return the fact that the
                 * intermediate name resolution failed.
                 * This is used to return an error of
                 * ERRbadpath rather than ERRbadfile.
                 * Some Windows applications depend on
                 * the difference between these two
                 * errors.
                 */

                /*
                 * ENOENT, ENOTDIR and ELOOP all map
                 * to NT_STATUS_OBJECT_PATH_NOT_FOUND
                 * in the filename walk.
                 */
                if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND) ||
                    NT_STATUS_EQUAL(status, NT_STATUS_STOPPED_ON_SYMLINK) ||
                    NT_STATUS_EQUAL(status, NT_STATUS_NOT_A_DIRECTORY)) {
                        status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                }
                return status;
        }

        /*
         * ENOENT/EACCESS are the only valid errors
         * here.
         */

        if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
                if ((state->ucf_flags & UCF_PREP_CREATEFILE) == 0) {
                        /*
                         * Could be a symlink pointing to
                         * a directory outside the share
                         * to which we don't have access.
                         * If so, we need to know that here
                         * so we can return the correct error code.
                         * check_name() is never called if we
                         * error out of filename_convert().
                         */
                        int ret;
                        struct smb_filename dname = (struct smb_filename) {
                                        .base_name = state->dirpath,
                                        .twrp = state->smb_fname->twrp,
                        };

                        /* handle null paths */
                        if ((dname.base_name == NULL) ||
                                        (dname.base_name[0] == '\0')) {
                                return NT_STATUS_ACCESS_DENIED;
                        }
                        ret = SMB_VFS_LSTAT(state->conn, &dname);
                        if (ret != 0) {
                                return NT_STATUS_ACCESS_DENIED;
                        }
                        if (!S_ISLNK(dname.st.st_ex_mode)) {
                                return NT_STATUS_ACCESS_DENIED;
                        }
                        status = check_name(state->conn, &dname);
                        if (!NT_STATUS_IS_OK(status)) {
                                /* We know this is an intermediate path. */
                                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
                        }
                        return NT_STATUS_ACCESS_DENIED;
                } else {
                        /*
                         * This is the dropbox
                         * behaviour. A dropbox is a
                         * directory with only -wx
                         * permissions, so
                         * get_real_filename fails
                         * with EACCESS, it needs to
                         * list the directory. We
                         * nevertheless want to allow
                         * users creating a file.
                         */
                        status = NT_STATUS_OK;
                }
        }

        if (!NT_STATUS_IS_OK(status) &&
            !NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
                /*
                 * ENOTDIR and ELOOP both map to
                 * NT_STATUS_OBJECT_PATH_NOT_FOUND
                 * in the filename walk.
                 */
                if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_A_DIRECTORY) ||
                    NT_STATUS_EQUAL(status, NT_STATUS_STOPPED_ON_SYMLINK)) {
                        status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                }
                return status;
        }

        /*
         * POSIX pathnames must never call into mangling.
         */
        if (state->posix_pathnames) {
                goto done;
        }

        /*
         * Just the last part of the name doesn't exist.
         * We need to strupper() or strlower() it as
         * this conversion may be used for file creation
         * purposes. Fix inspired by
         * Thomas Neumann <t.neumann@iku-ag.de>.
         */
        if (!state->case_preserve ||
            (mangle_is_8_3(state->name, false,
                           state->conn->params) &&
             !state->short_case_preserve)) {
                if (!strnorm(state->name,
                             lp_default_case(SNUM(state->conn)))) {
                        DBG_DEBUG("strnorm %s failed\n",
                                  state->name);
                        return NT_STATUS_INVALID_PARAMETER;
                }
        }

        /*
         * check on the mangled stack to see if we can
         * recover the base of the filename.
         */

        if (mangle_is_mangled(state->name, state->conn->params)
            && mangle_lookup_name_from_8_3(state->mem_ctx,
                                           state->name,
                                           &unmangled,
                                           state->conn->params)) {
                char *tmp;
                size_t name_ofs =
                        state->name - state->smb_fname->base_name;

                if (!ISDOT(state->dirpath)) {
                        tmp = talloc_asprintf(
                                state->smb_fname, "%s/%s",
                                state->dirpath, unmangled);
                        TALLOC_FREE(unmangled);
                }
                else {
                        tmp = unmangled;
                }
                if (tmp == NULL) {
                        DBG_ERR("talloc failed\n");
                        return NT_STATUS_NO_MEMORY;
                }
                TALLOC_FREE(state->smb_fname->base_name);
                state->smb_fname->base_name = tmp;
                state->name =
                        state->smb_fname->base_name + name_ofs;
                state->end = state->name + strlen(state->name);
        }

  done:

        DBG_DEBUG("New file [%s]\n", state->name);
        state->done = true;
        return NT_STATUS_OK;
}

static NTSTATUS unix_convert_step_stat(struct uc_state *state)
{
        struct smb_filename dname;
        char dot[2] = ".";
        char *found_name = NULL;
        int ret;
        NTSTATUS status;

        /*
         * Check if the name exists up to this point.
         */

        DBG_DEBUG("smb_fname [%s]\n", smb_fname_str_dbg(state->smb_fname));

        ret = vfs_stat(state->conn, state->smb_fname);
        if (ret == 0) {
                /*
                 * It exists. it must either be a directory or this must
                 * be the last part of the path for it to be OK.
                 */
                if (state->end && !S_ISDIR(state->smb_fname->st.st_ex_mode)) {
                        /*
                         * An intermediate part of the name isn't
                         * a directory.
                         */
                        DBG_DEBUG("Not a dir [%s]\n", state->name);
                        *state->end = '/';
                        /*
                         * We need to return the fact that the
                         * intermediate name resolution failed. This
                         * is used to return an error of ERRbadpath
                         * rather than ERRbadfile. Some Windows
                         * applications depend on the difference between
                         * these two errors.
                         */
                        return NT_STATUS_OBJECT_PATH_NOT_FOUND;
                }
                return NT_STATUS_OK;
        }

        /* Stat failed - ensure we don't use it. */
        SET_STAT_INVALID(state->smb_fname->st);

        if (state->posix_pathnames) {
                /*
                 * For posix_pathnames, we're done.
                 * Don't blunder into the
                 * get_real_filename() codepath as they may
                 * be doing case insensitive lookups. So when
                 * creating a new POSIX directory Foo they might
                 * match on name foo.
                 *
                 * BUG: https://bugzilla.samba.org/show_bug.cgi?id=13803
                 */
                if (state->end != NULL) {
                        const char *morepath = NULL;
                        /*
                         * If this is intermediate we must
                         * restore the full path.
                         */
                        *state->end = '/';
                        /*
                         * If there are any more components
                         * after the failed LSTAT we cannot
                         * continue.
                         */
                        morepath = strchr(state->end + 1, '/');
                        if (morepath != NULL) {
                                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
                        }
                }
                if (errno == ENOENT) {
                        /* New file or directory. */
                        state->done = true;
                        return NT_STATUS_OK;
                }
                if ((errno == EACCES) &&
                    (state->ucf_flags & UCF_PREP_CREATEFILE)) {
                        /* POSIX Dropbox case. */
                        errno = 0;
                        state->done = true;
                        return NT_STATUS_OK;
                }
                return map_nt_error_from_unix(errno);
        }

        /*
         * Reset errno so we can detect
         * directory open errors.
         */
        errno = 0;

        /*
         * Try to find this part of the path in the directory.
         */

        dname = (struct smb_filename) {
                .base_name = state->dirpath,
                .twrp = state->smb_fname->twrp,
        };

        /* handle null paths */
        if ((dname.base_name == NULL) || (dname.base_name[0] == '\0')) {
                dname.base_name = dot;
        }

        status = get_real_filename(state->conn,
                                   &dname,
                                   state->name,
                                   talloc_tos(),
                                   &found_name);
        if (!NT_STATUS_IS_OK(status)) {
                return unix_convert_step_search_fail(state, status);
        }

        /*
         * Restore the rest of the string. If the string was
         * mangled the size may have changed.
         */
        if (state->end) {
                char *tmp;
                size_t name_ofs =
                        state->name - state->smb_fname->base_name;

                if (!ISDOT(state->dirpath)) {
                        tmp = talloc_asprintf(state->smb_fname,
                                              "%s/%s/%s", state->dirpath,
                                              found_name, state->end+1);
                }
                else {
                        tmp = talloc_asprintf(state->smb_fname,
                                              "%s/%s", found_name,
                                              state->end+1);
                }
                if (tmp == NULL) {
                        DBG_ERR("talloc_asprintf failed\n");
                        return NT_STATUS_NO_MEMORY;
                }
                TALLOC_FREE(state->smb_fname->base_name);
                state->smb_fname->base_name = tmp;
                state->name = state->smb_fname->base_name + name_ofs;
                state->end = state->name + strlen(found_name);
                *state->end = '\0';
        } else {
                char *tmp;
                size_t name_ofs =
                        state->name - state->smb_fname->base_name;

                if (!ISDOT(state->dirpath)) {
                        tmp = talloc_asprintf(state->smb_fname,
                                              "%s/%s", state->dirpath,
                                              found_name);
                } else {
                        tmp = talloc_strdup(state->smb_fname,
                                            found_name);
                }
                if (tmp == NULL) {
                        DBG_ERR("talloc failed\n");
                        return NT_STATUS_NO_MEMORY;
                }
                TALLOC_FREE(state->smb_fname->base_name);
                state->smb_fname->base_name = tmp;
                state->name = state->smb_fname->base_name + name_ofs;

                /*
                 * We just scanned for, and found the end of
                 * the path. We must return a valid stat struct
                 * if it exists. JRA.
                 */

                ret = vfs_stat(state->conn, state->smb_fname);
                if (ret != 0) {
                        SET_STAT_INVALID(state->smb_fname->st);
                }
        }

        TALLOC_FREE(found_name);
        return NT_STATUS_OK;
}

static NTSTATUS unix_convert_step(struct uc_state *state)
{
        NTSTATUS status;

        /*
         * Pinpoint the end of this section of the filename.
         */
        /* mb safe. '/' can't be in any encoded char. */
        state->end = strchr(state->name, '/');

        /*
         * Chop the name at this point.
         */
        if (state->end != NULL) {
                *state->end = 0;
        }

        DBG_DEBUG("dirpath [%s] name [%s]\n", state->dirpath, state->name);

        /* The name cannot have a component of "." */

        if (ISDOT(state->name)) {
                if (state->end == NULL)  {
                        /* Error code at the end of a pathname. */
                        return NT_STATUS_OBJECT_NAME_INVALID;
                }
                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
        }

        status = unix_convert_step_stat(state);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }
        if (state->done) {
                return NT_STATUS_OK;
        }

        /*
         * Add to the dirpath that we have resolved so far.
         */

        if (!ISDOT(state->dirpath)) {
                char *tmp = talloc_asprintf(state->mem_ctx,
                                            "%s/%s", state->dirpath, state->name);
                if (!tmp) {
                        DBG_ERR("talloc_asprintf failed\n");
                        return NT_STATUS_NO_MEMORY;
                }
                TALLOC_FREE(state->dirpath);
                state->dirpath = tmp;
        }
        else {
                TALLOC_FREE(state->dirpath);
                if (!(state->dirpath = talloc_strdup(state->mem_ctx,state->name))) {
                        DBG_ERR("talloc_strdup failed\n");
                        return NT_STATUS_NO_MEMORY;
                }
        }

        /*
         * Cache the dirpath thus far. Don't cache a name with mangled
         * components as this can change the size.
         */
        if(!state->component_was_mangled) {
                stat_cache_add(state->orig_path,
                               state->dirpath,
                               state->smb_fname->twrp,
                               state->case_sensitive);
        }

        /*
         * Restore the / that we wiped out earlier.
         */
        if (state->end != NULL) {
                *state->end = '/';
        }

        return NT_STATUS_OK;
}

NTSTATUS unix_convert(TALLOC_CTX *mem_ctx,
                      connection_struct *conn,
                      const char *orig_path,
                      NTTIME twrp,
                      struct smb_filename **smb_fname_out,
                      uint32_t ucf_flags)
{
        struct uc_state uc_state;
        struct uc_state *state = &uc_state;
        NTSTATUS status;
        int ret = -1;
        int parent_stat_errno = 0;

        *state = (struct uc_state) {
                .mem_ctx = mem_ctx,
                .conn = conn,
                .orig_path = orig_path,
                .ucf_flags = ucf_flags,
                .posix_pathnames = (ucf_flags & UCF_POSIX_PATHNAMES),
                .case_sensitive = conn->case_sensitive,
                .case_preserve = conn->case_preserve,
                .short_case_preserve = conn->short_case_preserve,
        };

        *smb_fname_out = NULL;

        if (state->posix_pathnames) {
                /* POSIX means ignore case settings on share. */
                state->case_sensitive = true;
                state->case_preserve = true;
                state->short_case_preserve = true;
        }

        state->smb_fname = talloc_zero(state->mem_ctx, struct smb_filename);
        if (state->smb_fname == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        if (state->conn->printer) {
                /* we don't ever use the filenames on a printer share as a
                        filename - so don't convert them */
                state->smb_fname->base_name = talloc_strdup(
                        state->smb_fname, state->orig_path);
                if (state->smb_fname->base_name == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto err;
                }
                goto done;
        }

        state->smb_fname->flags = state->posix_pathnames ? SMB_FILENAME_POSIX_PATH : 0;

        DBG_DEBUG("Called on file [%s]\n", state->orig_path);

        if (state->orig_path[0] == '/') {
                DBG_ERR("Path [%s] starts with '/'\n", state->orig_path);
                return NT_STATUS_OBJECT_NAME_INVALID;
        }

        /* Start with the full orig_path as given by the caller. */
        state->smb_fname->base_name = talloc_strdup(
                state->smb_fname, state->orig_path);
        if (state->smb_fname->base_name == NULL) {
                DBG_ERR("talloc_strdup failed\n");
                status = NT_STATUS_NO_MEMORY;
                goto err;
        }

        /* Canonicalize any @GMT- paths. */
        status = canonicalize_snapshot_path(state->smb_fname, ucf_flags, twrp);
        if (!NT_STATUS_IS_OK(status)) {
                goto err;
        }

        /*
         * If we trimmed down to a single '\0' character
         * then we should use the "." directory to avoid
         * searching the cache, but not if we are in a
         * printing share.
         * As we know this is valid we can return true here.
         */

        if (state->smb_fname->base_name[0] == '\0') {
                state->smb_fname->base_name = talloc_strdup(state->smb_fname, ".");
                if (state->smb_fname->base_name == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto err;
                }
                if (SMB_VFS_STAT(state->conn, state->smb_fname) != 0) {
                        status = map_nt_error_from_unix(errno);
                        goto err;
                }
                DBG_DEBUG("conversion finished [] -> [%s]\n",
                          state->smb_fname->base_name);
                goto done;
        }

        if (state->orig_path[0] == '.' && (state->orig_path[1] == '/' ||
                                state->orig_path[1] == '\0')) {
                /* Start of pathname can't be "." only. */
                if (state->orig_path[1] == '\0' || state->orig_path[2] == '\0') {
                        status = NT_STATUS_OBJECT_NAME_INVALID;
                } else {
                        status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                }
                goto err;
        }

        /*
         * Large directory fix normalization. If we're case sensitive, and
         * the case preserving parameters are set to "no", normalize the case of
         * the incoming filename from the client WHETHER IT EXISTS OR NOT !
         * This is in conflict with the current (3.0.20) man page, but is
         * what people expect from the "large directory howto". I'll update
         * the man page. Thanks to jht@samba.org for finding this. JRA.
         */

        status = normalize_filename_case(state->conn,
                                         state->smb_fname->base_name,
                                         ucf_flags);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_ERR("normalize_filename_case %s failed\n",
                                state->smb_fname->base_name);
                goto err;
        }

        /*
         * Strip off the stream, and add it back when we're done with the
         * base_name.
         */
        if (!state->posix_pathnames) {
                state->stream = strchr_m(state->smb_fname->base_name, ':');

                if (state->stream != NULL) {
                        char *tmp = talloc_strdup(state->smb_fname, state->stream);
                        if (tmp == NULL) {
                                status = NT_STATUS_NO_MEMORY;
                                goto err;
                        }
                        /*
                         * Since this is actually pointing into
                         * smb_fname->base_name this truncates base_name.
                         */
                        *state->stream = '\0';
                        state->stream = tmp;

                        if (state->smb_fname->base_name[0] == '\0') {
                                /*
                                 * orig_name was just a stream name.
                                 * This is a stream on the root of
                                 * the share. Replace base_name with
                                 * a "."
                                 */
                                state->smb_fname->base_name =
                                        talloc_strdup(state->smb_fname, ".");
                                if (state->smb_fname->base_name == NULL) {
                                        status = NT_STATUS_NO_MEMORY;
                                        goto err;
                                }
                                if (SMB_VFS_STAT(state->conn, state->smb_fname) != 0) {
                                        status = map_nt_error_from_unix(errno);
                                        goto err;
                                }
                                /* dirpath must exist. */
                                state->dirpath = talloc_strdup(state->mem_ctx,".");
                                if (state->dirpath == NULL) {
                                        status = NT_STATUS_NO_MEMORY;
                                        goto err;
                                }
                                DBG_INFO("conversion finished [%s] -> [%s]\n",
                                         state->orig_path,
                                         state->smb_fname->base_name);
                                goto done;
                        }
                }
        }

        state->name = state->smb_fname->base_name;

        /*
         * If we're providing case insensitive semantics or
         * the underlying filesystem is case insensitive,
         * then a case-normalized hit in the stat-cache is
         * authoritative. JRA.
         *
         * Note: We're only checking base_name.  The stream_name will be
         * added and verified in build_stream_path().
         */

        if (!state->case_sensitive ||
            !(state->conn->fs_capabilities & FILE_CASE_SENSITIVE_SEARCH))
        {
                bool found;

                found = stat_cache_lookup(state->conn,
                                          &state->smb_fname->base_name,
                                          &state->dirpath,
                                          &state->name,
                                          state->smb_fname->twrp,
                                          &state->smb_fname->st);
                /*
                 * stat_cache_lookup() allocates on talloc_tos() even
                 * when !found, reparent correctly
                 */
                talloc_steal(state->smb_fname, state->smb_fname->base_name);
                talloc_steal(state->mem_ctx, state->dirpath);

                if (found) {
                        goto done;
                }
        }

        /*
         * Make sure "dirpath" is an allocated string, we use this for
         * building the directories with talloc_asprintf and free it.
         */

        if (state->dirpath == NULL) {
                state->dirpath = talloc_strdup(state->mem_ctx,".");
                if (state->dirpath == NULL) {
                        DBG_ERR("talloc_strdup failed\n");
                        status = NT_STATUS_NO_MEMORY;
                        goto err;
                }
        }

        /*
         * If we have a wildcard we must walk the path to
         * find where the error is, even if case sensitive
         * is true.
         */

        if (!state->posix_pathnames) {
                /* POSIX pathnames have no wildcards. */
                bool name_has_wildcard = ms_has_wild(state->smb_fname->base_name);
                if (name_has_wildcard) {
                        /* Wildcard not valid anywhere. */
                        status = NT_STATUS_OBJECT_NAME_INVALID;
                        goto fail;
                }
        }

        DBG_DEBUG("Begin: name [%s] dirpath [%s] name [%s]\n",
                  state->smb_fname->base_name, state->dirpath, state->name);

        /*
         * stat the name - if it exists then we can add the stream back (if
         * there was one) and be done!
         */

        ret = vfs_stat(state->conn, state->smb_fname);
        if (ret == 0) {
                status = check_for_dot_component(state->smb_fname);
                if (!NT_STATUS_IS_OK(status)) {
                        goto fail;
                }
                /* Add the path (not including the stream) to the cache. */
                stat_cache_add(state->orig_path,
                               state->smb_fname->base_name,
                               state->smb_fname->twrp,
                               state->case_sensitive);
                DBG_DEBUG("Conversion of base_name finished "
                          "[%s] -> [%s]\n",
                          state->orig_path, state->smb_fname->base_name);
                goto done;
        }

        /* Stat failed - ensure we don't use it. */
        SET_STAT_INVALID(state->smb_fname->st);

        /*
         * Note: we must continue processing a path if we get EACCES
         * from stat. With NFS4 permissions the file might be lacking
         * READ_ATTR, but if the parent has LIST permissions we can
         * resolve the path in the path traversal loop down below.
         */

        if (errno == ENOENT) {
                /* Optimization when creating a new file - only
                   the last component doesn't exist.
                   NOTE : check_parent_exists() doesn't preserve errno.
                */
                int saved_errno = errno;
                status = check_parent_exists(state->mem_ctx,
                                        state->conn,
                                        state->posix_pathnames,
                                        state->smb_fname,
                                        &state->dirpath,
                                        &state->name,
                                        &parent_stat_errno);
                errno = saved_errno;
                if (!NT_STATUS_IS_OK(status)) {
                        goto fail;
                }
        }

        /*
         * A special case - if we don't have any wildcards or mangling chars and are case
         * sensitive or the underlying filesystem is case insensitive then searching
         * won't help.
         *
         * NB. As POSIX sets state->case_sensitive as
         * true we will never call into mangle_is_mangled() here.
         */

        if ((state->case_sensitive || !(state->conn->fs_capabilities &
                                FILE_CASE_SENSITIVE_SEARCH)) &&
                        !mangle_is_mangled(state->smb_fname->base_name, state->conn->params)) {

                status = check_for_dot_component(state->smb_fname);
                if (!NT_STATUS_IS_OK(status)) {
                        goto fail;
                }

                /*
                 * The stat failed. Could be ok as it could be
                 * a new file.
                 */

                if (errno == ENOTDIR || errno == ELOOP) {
                        status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                        goto fail;
                } else if (errno == ENOENT) {
                        /*
                         * Was it a missing last component ?
                         * or a missing intermediate component ?
                         *
                         * Optimization.
                         *
                         * For this code path we can guarantee that
                         * we have gone through check_parent_exists()
                         * and it returned NT_STATUS_OK.
                         *
                         * Either there was no parent component (".")
                         * parent_stat_errno == 0 and we have a missing
                         * last component here.
                         *
                         * OR check_parent_exists() called STAT/LSTAT
                         * and if it failed parent_stat_errno has been
                         * set telling us if the parent existed or not.
                         *
                         * Either way we can avoid another STAT/LSTAT
                         * system call on the parent here.
                         */
                        if (parent_stat_errno == ENOTDIR ||
                                        parent_stat_errno == ENOENT ||
                                        parent_stat_errno == ELOOP) {
                                status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                                goto fail;
                        }

                        /*
                         * Missing last component is ok - new file.
                         * Also deal with permission denied elsewhere.
                         * Just drop out to done.
                         */
                        goto done;
                }
        }

        /*
         * is_mangled() was changed to look at an entire pathname, not
         * just a component. JRA.
         */

        if (state->posix_pathnames) {
                /*
                 * POSIX names are never mangled and we must not
                 * call into mangling functions.
                 */
                state->component_was_mangled = false;
        } else if (mangle_is_mangled(state->name, state->conn->params)) {
                state->component_was_mangled = true;
        }

        /*
         * Now we need to recursively match the name against the real
         * directory structure.
         */

        /*
         * Match each part of the path name separately, trying the names
         * as is first, then trying to scan the directory for matching names.
         */

        for (; state->name ; state->name = (state->end ? state->end + 1:(char *)NULL)) {
                status = unix_convert_step(state);
                if (!NT_STATUS_IS_OK(status)) {
                        if (NT_STATUS_EQUAL(status, NT_STATUS_NO_MEMORY)) {
                                goto err;
                        }
                        goto fail;
                }
                if (state->done) {
                        goto done;
                }
        }

        /*
         * Cache the full path. Don't cache a name with mangled or wildcard
         * components as this can change the size.
         */

        if(!state->component_was_mangled) {
                stat_cache_add(state->orig_path,
                               state->smb_fname->base_name,
                               state->smb_fname->twrp,
                               state->case_sensitive);
        }

        /*
         * The name has been resolved.
         */

 done:
        /* Add back the stream if one was stripped off originally. */
        if (state->stream != NULL) {
                state->smb_fname->stream_name = state->stream;

                /* Check path now that the base_name has been converted. */
                status = build_stream_path(state->mem_ctx, state->conn, state->smb_fname);
                if (!NT_STATUS_IS_OK(status)) {
                        goto fail;
                }
        }

        DBG_DEBUG("Conversion finished [%s] -> [%s]\n",
                   state->orig_path, smb_fname_str_dbg(state->smb_fname));

        TALLOC_FREE(state->dirpath);
        *smb_fname_out = state->smb_fname;
        return NT_STATUS_OK;
 fail:
        DBG_DEBUG("Conversion failed: dirpath [%s] name [%s]\n",
                  state->dirpath, state->name);
        if ((state->dirpath != NULL) && !ISDOT(state->dirpath)) {
                state->smb_fname->base_name = talloc_asprintf(
                        state->smb_fname,
                        "%s/%s",
                        state->dirpath,
                        state->name);
        } else {
                state->smb_fname->base_name = talloc_strdup(
                        state->smb_fname, state->name);
        }
        if (state->smb_fname->base_name == NULL) {
                DBG_ERR("talloc_asprintf failed\n");
                status = NT_STATUS_NO_MEMORY;
                goto err;
        }

        *smb_fname_out = state->smb_fname;
        TALLOC_FREE(state->dirpath);
        return status;
 err:
        TALLOC_FREE(state->smb_fname);
        return status;
}

/****************************************************************************
 Ensure a path is not vetoed.
****************************************************************************/

static NTSTATUS check_veto_path(connection_struct *conn,
                        const struct smb_filename *smb_fname)
{
        const char *name = smb_fname->base_name;

        if (IS_VETO_PATH(conn, name))  {
                /* Is it not dot or dot dot. */
                if (!(ISDOT(name) || ISDOTDOT(name))) {
                        DEBUG(5,("check_veto_path: file path name %s vetoed\n",
                                                name));
                        return map_nt_error_from_unix(ENOENT);
                }
        }
        return NT_STATUS_OK;
}

/****************************************************************************
 Check a filename - possibly calling check_reduced_name.
 This is called by every routine before it allows an operation on a filename.
 It does any final confirmation necessary to ensure that the filename is
 a valid one for the user to access.
****************************************************************************/

static NTSTATUS check_name(connection_struct *conn,
                        const struct smb_filename *smb_fname)
{
        NTSTATUS status = check_veto_path(conn, smb_fname);

        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        if (!lp_widelinks(SNUM(conn)) || !lp_follow_symlinks(SNUM(conn))) {
                status = check_reduced_name(conn, NULL, smb_fname);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(5,("check_name: name %s failed with %s\n",
                                        smb_fname->base_name,
                                        nt_errstr(status)));
                        return status;
                }
        }

        return NT_STATUS_OK;
}

/****************************************************************************
 Check if two filenames are equal.
 This needs to be careful about whether we are case sensitive.
****************************************************************************/

static bool fname_equal(const char *name1, const char *name2,
                bool case_sensitive)
{
        /* Normal filename handling */
        if (case_sensitive) {
                return(strcmp(name1,name2) == 0);
        }

        return(strequal(name1,name2));
}

static bool sname_equal(const char *name1, const char *name2,
                bool case_sensitive)
{
        bool match;
        const char *s1 = NULL;
        const char *s2 = NULL;
        size_t n1;
        size_t n2;
        const char *e1 = NULL;
        const char *e2 = NULL;
        char *c1 = NULL;
        char *c2 = NULL;

        match = fname_equal(name1, name2, case_sensitive);
        if (match) {
                return true;
        }

        if (name1[0] != ':') {
                return false;
        }
        if (name2[0] != ':') {
                return false;
        }
        s1 = &name1[1];
        e1 = strchr(s1, ':');
        if (e1 == NULL) {
                n1 = strlen(s1);
        } else {
                n1 = PTR_DIFF(e1, s1);
        }
        s2 = &name2[1];
        e2 = strchr(s2, ':');
        if (e2 == NULL) {
                n2 = strlen(s2);
        } else {
                n2 = PTR_DIFF(e2, s2);
        }

        /* Normal filename handling */
        if (case_sensitive) {
                return (strncmp(s1, s2, n1) == 0);
        }

        /*
         * We can't use strnequal() here
         * as it takes the number of codepoints
         * and not the number of bytes.
         *
         * So we make a copy before calling
         * strequal().
         *
         * Note that we TALLOC_FREE() in reverse order
         * in order to avoid memory fragmentation.
         */

        c1 = talloc_strndup(talloc_tos(), s1, n1);
        c2 = talloc_strndup(talloc_tos(), s2, n2);
        if (c1 == NULL || c2 == NULL) {
                TALLOC_FREE(c2);
                TALLOC_FREE(c1);
                return (strncmp(s1, s2, n1) == 0);
        }

        match = strequal(c1, c2);
        TALLOC_FREE(c2);
        TALLOC_FREE(c1);
        return match;
}

/****************************************************************************
 Scan a directory to find a filename, matching without case sensitivity.
 If the name looks like a mangled name then try via the mangling functions
****************************************************************************/

NTSTATUS get_real_filename_full_scan_at(struct files_struct *dirfsp,
                                        const char *name,
                                        bool mangled,
                                        TALLOC_CTX *mem_ctx,
                                        char **found_name)
{
        struct connection_struct *conn = dirfsp->conn;
        struct smb_Dir *cur_dir = NULL;
        const char *dname = NULL;
        char *talloced = NULL;
        char *unmangled_name = NULL;
        long curpos;
        NTSTATUS status;

        /* If we have a case-sensitive filesystem, it doesn't do us any
         * good to search for a name. If a case variation of the name was
         * there, then the original stat(2) would have found it.
         */
        if (!mangled && !(conn->fs_capabilities & FILE_CASE_SENSITIVE_SEARCH)) {
                return NT_STATUS_OBJECT_NAME_NOT_FOUND;
        }

        /*
         * The incoming name can be mangled, and if we de-mangle it
         * here it will not compare correctly against the filename (name2)
         * read from the directory and then mangled by the name_to_8_3()
         * call. We need to mangle both names or neither.
         * (JRA).
         *
         * Fix for bug found by Dina Fine. If in case sensitive mode then
         * the mangle cache is no good (3 letter extension could be wrong
         * case - so don't demangle in this case - leave as mangled and
         * allow the mangling of the directory entry read (which is done
         * case insensitively) to match instead. This will lead to more
         * false positive matches but we fail completely without it. JRA.
         */

        if (mangled && !conn->case_sensitive) {
                mangled = !mangle_lookup_name_from_8_3(talloc_tos(), name,
                                                       &unmangled_name,
                                                       conn->params);
                if (!mangled) {
                        /* Name is now unmangled. */
                        name = unmangled_name;
                }
        }

        /* open the directory */
        status = OpenDir_from_pathref(talloc_tos(), dirfsp, NULL, 0, &cur_dir);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_NOTICE("scan dir didn't open dir [%s]: %s\n",
                           fsp_str_dbg(dirfsp),
                           nt_errstr(status));
                TALLOC_FREE(unmangled_name);
                return status;
        }

        /* now scan for matching names */
        curpos = 0;
        while ((dname = ReadDirName(cur_dir, &curpos, NULL, &talloced))) {

                /* Is it dot or dot dot. */
                if (ISDOT(dname) || ISDOTDOT(dname)) {
                        TALLOC_FREE(talloced);
                        continue;
                }

                /*
                 * At this point dname is the unmangled name.
                 * name is either mangled or not, depending on the state
                 * of the "mangled" variable. JRA.
                 */

                /*
                 * Check mangled name against mangled name, or unmangled name
                 * against unmangled name.
                 */

                if ((mangled && mangled_equal(name,dname,conn->params)) ||
                        fname_equal(name, dname, conn->case_sensitive)) {
                        /* we've found the file, change it's name and return */
                        *found_name = talloc_strdup(mem_ctx, dname);
                        TALLOC_FREE(unmangled_name);
                        TALLOC_FREE(cur_dir);
                        if (!*found_name) {
                                TALLOC_FREE(talloced);
                                return NT_STATUS_NO_MEMORY;
                        }
                        TALLOC_FREE(talloced);
                        return NT_STATUS_OK;
                }
                TALLOC_FREE(talloced);
        }

        TALLOC_FREE(unmangled_name);
        TALLOC_FREE(cur_dir);
        return NT_STATUS_OBJECT_NAME_NOT_FOUND;
}

NTSTATUS get_real_filename_full_scan(connection_struct *conn,
                                     const char *path,
                                     const char *name,
                                     bool mangled,
                                     TALLOC_CTX *mem_ctx,
                                     char **found_name)
{
        struct smb_filename *smb_dname = NULL;
        NTSTATUS status;

        /* handle null paths */
        if ((path == NULL) || (*path == 0)) {
                path = ".";
        }

        status = synthetic_pathref(
                talloc_tos(),
                conn->cwd_fsp,
                path,
                NULL,
                NULL,
                0,
                0,
                &smb_dname);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        status = get_real_filename_full_scan_at(
                smb_dname->fsp, name, mangled, mem_ctx, found_name);

        TALLOC_FREE(smb_dname);
        return status;
}

/****************************************************************************
 Wrapper around the vfs get_real_filename and the full directory scan
 fallback.
****************************************************************************/

NTSTATUS get_real_filename_at(struct files_struct *dirfsp,
                              const char *name,
                              TALLOC_CTX *mem_ctx,
                              char **found_name)
{
        struct connection_struct *conn = dirfsp->conn;
        NTSTATUS status;
        bool mangled;

        mangled = mangle_is_mangled(name, conn->params);

        if (mangled) {
                status = get_real_filename_full_scan_at(
                        dirfsp, name, mangled, mem_ctx, found_name);
                return status;
        }

        /* Try the vfs first to take advantage of case-insensitive stat. */
        status = SMB_VFS_GET_REAL_FILENAME_AT(
                dirfsp->conn, dirfsp, name, mem_ctx, found_name);

        /*
         * If the case-insensitive stat was successful, or returned an error
         * other than EOPNOTSUPP then there is no need to fall back on the
         * full directory scan.
         */
        if (NT_STATUS_IS_OK(status) ||
            !NT_STATUS_EQUAL(status, NT_STATUS_NOT_SUPPORTED)) {
                return status;
        }

        status = get_real_filename_full_scan_at(
                dirfsp, name, mangled, mem_ctx, found_name);
        return status;
}

/*
 * Create the memcache-key for GETREALFILENAME_CACHE: This supplements
 * the stat cache for the last component to be looked up. Cache
 * contents is the correctly capitalized translation of the parameter
 * "name" as it exists on disk. This is indexed by inode of the dirfsp
 * and name, and contrary to stat_cahce_lookup() it does not
 * vfs_stat() the last component. This will be taken care of by an
 * attempt to do a openat_pathref_fsp().
 */
static bool get_real_filename_cache_key(
        TALLOC_CTX *mem_ctx,
        struct files_struct *dirfsp,
        const char *name,
        DATA_BLOB *_key)
{
        struct file_id fid = vfs_file_id_from_sbuf(
                dirfsp->conn, &dirfsp->fsp_name->st);
        char *upper = NULL;
        uint8_t *key = NULL;
        size_t namelen, keylen;

        upper = talloc_strdup_upper(mem_ctx, name);
        if (upper == NULL) {
                return false;
        }
        namelen = talloc_get_size(upper);

        keylen = namelen + sizeof(fid);
        if (keylen < sizeof(fid)) {
                TALLOC_FREE(upper);
                return false;
        }

        key = talloc_size(mem_ctx, keylen);
        if (key == NULL) {
                TALLOC_FREE(upper);
                return false;
        }

        memcpy(key, &fid, sizeof(fid));
        memcpy(key + sizeof(fid), upper, namelen);
        TALLOC_FREE(upper);

        *_key = (DATA_BLOB) { .data = key, .length = keylen, };
        return true;
}

static NTSTATUS get_real_filename(connection_struct *conn,
                                  struct smb_filename *path,
                                  const char *name,
                                  TALLOC_CTX *mem_ctx,
                                  char **found_name)
{
        struct smb_filename *smb_dname = NULL;
        NTSTATUS status;

        smb_dname = cp_smb_filename_nostream(talloc_tos(), path);
        if (smb_dname == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

again:
        status = openat_pathref_fsp(conn->cwd_fsp, smb_dname);

        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND) &&
            S_ISLNK(smb_dname->st.st_ex_mode)) {
                status = NT_STATUS_STOPPED_ON_SYMLINK;
        }

        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND) &&
            (smb_dname->twrp != 0)) {
                /*
                 * Retry looking at the non-snapshot path, copying the
                 * fallback mechanism from vfs_shadow_copy2.c when
                 * shadow_copy2_convert() fails. This path-based
                 * routine get_real_filename() should go away and be
                 * replaced with a fd-based one, so spoiling it with a
                 * shadow_copy2 specific mechanism should not be too
                 * bad.
                 */
                smb_dname->twrp = 0;
                goto again;
        }

        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("openat_pathref_fsp(%s) failed: %s\n",
                          smb_fname_str_dbg(smb_dname),
                          nt_errstr(status));

                /*
                 * ENOTDIR and ELOOP both map to
                 * NT_STATUS_OBJECT_PATH_NOT_FOUND in the filename
                 * walk.
                 */
                if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_A_DIRECTORY) ||
                    NT_STATUS_EQUAL(status, NT_STATUS_STOPPED_ON_SYMLINK)) {
                        status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                }

                return status;
        }

        status = get_real_filename_at(
                smb_dname->fsp, name, mem_ctx, found_name);
        TALLOC_FREE(smb_dname);
        return status;
}

static NTSTATUS build_stream_path(TALLOC_CTX *mem_ctx,
                                  connection_struct *conn,
                                  struct smb_filename *smb_fname)
{
        NTSTATUS status;
        unsigned int i, num_streams = 0;
        struct stream_struct *streams = NULL;
        struct smb_filename *pathref = NULL;

        if (SMB_VFS_STAT(conn, smb_fname) == 0) {
                DEBUG(10, ("'%s' exists\n", smb_fname_str_dbg(smb_fname)));
                return NT_STATUS_OK;
        }

        if (errno != ENOENT) {
                DEBUG(10, ("vfs_stat failed: %s\n", strerror(errno)));
                status = map_nt_error_from_unix(errno);
                goto fail;
        }

        if (smb_fname->fsp == NULL) {
                status = synthetic_pathref(mem_ctx,
                                        conn->cwd_fsp,
                                        smb_fname->base_name,
                                        NULL,
                                        NULL,
                                        smb_fname->twrp,
                                        smb_fname->flags,
                                        &pathref);
                if (!NT_STATUS_IS_OK(status)) {
                        if (NT_STATUS_EQUAL(status,
                                NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
                                TALLOC_FREE(pathref);
                                SET_STAT_INVALID(smb_fname->st);
                                return NT_STATUS_OK;
                        }
                        DBG_DEBUG("synthetic_pathref failed: %s\n",
                                  nt_errstr(status));
                        goto fail;
                }
        } else {
                pathref = smb_fname;
        }

        /* Fall back to a case-insensitive scan of all streams on the file. */
        status = vfs_fstreaminfo(pathref->fsp, mem_ctx,
                                &num_streams, &streams);
        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
                SET_STAT_INVALID(smb_fname->st);
                TALLOC_FREE(pathref);
                return NT_STATUS_OK;
        }

        if (!NT_STATUS_IS_OK(status)) {
                DEBUG(10, ("vfs_fstreaminfo failed: %s\n", nt_errstr(status)));
                goto fail;
        }

        for (i=0; i<num_streams; i++) {
                bool equal = sname_equal(
                        smb_fname->stream_name,
                        streams[i].name,
                        conn->case_sensitive);

                DBG_DEBUG("comparing [%s] and [%s]: %sequal\n",
                          smb_fname->stream_name,
                          streams[i].name,
                          equal ? "" : "not ");

                if (equal) {
                        break;
                }
        }

        /* Couldn't find the stream. */
        if (i == num_streams) {
                SET_STAT_INVALID(smb_fname->st);
                TALLOC_FREE(pathref);
                TALLOC_FREE(streams);
                return NT_STATUS_OK;
        }

        DEBUG(10, ("case insensitive stream. requested: %s, actual: %s\n",
                smb_fname->stream_name, streams[i].name));


        TALLOC_FREE(smb_fname->stream_name);
        smb_fname->stream_name = talloc_strdup(smb_fname, streams[i].name);
        if (smb_fname->stream_name == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto fail;
        }

        SET_STAT_INVALID(smb_fname->st);

        if (SMB_VFS_STAT(conn, smb_fname) == 0) {
                DEBUG(10, ("'%s' exists\n", smb_fname_str_dbg(smb_fname)));
        }
        status = NT_STATUS_OK;
 fail:
        TALLOC_FREE(pathref);
        TALLOC_FREE(streams);
        return status;
}

/*
 * Lightweight function to just get last component
 * for rename / enumerate directory calls.
 */

char *get_original_lcomp(TALLOC_CTX *ctx,
                        connection_struct *conn,
                        const char *filename_in,
                        uint32_t ucf_flags)
{
        struct smb_filename *smb_fname = NULL;
        char *last_slash = NULL;
        char *orig_lcomp;
        char *fname = NULL;
        NTTIME twrp = 0;
        NTSTATUS status;

        if (ucf_flags & UCF_DFS_PATHNAME) {
                status = dfs_redirect(ctx,
                                conn,
                                filename_in,
                                ucf_flags,
                                !conn->sconn->using_smb2,
                                &twrp,
                                &fname);
                if (!NT_STATUS_IS_OK(status)) {
                        DBG_DEBUG("dfs_redirect "
                                "failed for name %s with %s\n",
                                filename_in,
                                nt_errstr(status));
                        return NULL;
                }
                filename_in = fname;
                ucf_flags &= ~UCF_DFS_PATHNAME;
        }

        /*
         * NB. We don't need to care about
         * is_fake_file_path(filename_in) here as these
         * code paths don't ever return original_lcomp
         * or use it anyway.
         */

        if (ucf_flags & UCF_GMT_PATHNAME) {
                /*
                 * Ensure we don't return a @GMT
                 * value as the last component.
                 */
                smb_fname = synthetic_smb_fname(ctx,
                                        filename_in,
                                        NULL,
                                        NULL,
                                        twrp,
                                        0);
                if (smb_fname == NULL) {
                        TALLOC_FREE(fname);
                        return NULL;
                }
                status = canonicalize_snapshot_path(smb_fname,
                                                    ucf_flags,
                                                    twrp);
                if (!NT_STATUS_IS_OK(status)) {
                        TALLOC_FREE(fname);
                        TALLOC_FREE(smb_fname);
                        return NULL;
                }
                filename_in = smb_fname->base_name;
        }
        last_slash = strrchr(filename_in, '/');
        if (last_slash != NULL) {
                orig_lcomp = talloc_strdup(ctx, last_slash+1);
        } else {
                orig_lcomp = talloc_strdup(ctx, filename_in);
        }
        /* We're done with any temp names here. */
        TALLOC_FREE(smb_fname);
        TALLOC_FREE(fname);
        if (orig_lcomp == NULL) {
                return NULL;
        }
        status = normalize_filename_case(conn, orig_lcomp, ucf_flags);
        if (!NT_STATUS_IS_OK(status)) {
                TALLOC_FREE(orig_lcomp);
                return NULL;
        }
        return orig_lcomp;
}

/**
 * Go through all the steps to validate a filename.
 *
 * @param ctx           talloc_ctx to allocate memory with.
 * @param conn          connection struct for vfs calls.
 * @param smbreq        SMB request if we're using privileges.
 * @param name_in       The unconverted name.
 * @param ucf_flags     flags to pass through to unix_convert().
 * @param twrp          Optional VSS time
 * @param p_cont_wcard  If not NULL, will be set to true if the dfs path
 *                      resolution detects a wildcard.
 * @param _smb_fname    The final converted name will be allocated if the
 *                      return is NT_STATUS_OK.
 *
 * @return NT_STATUS_OK if all operations completed successfully, appropriate
 *         error otherwise.
 */
NTSTATUS filename_convert(TALLOC_CTX *ctx,
                          connection_struct *conn,
                          const char *name_in,
                          uint32_t ucf_flags,
                          NTTIME twrp,
                          struct smb_filename **_smb_fname)
{
        struct smb_filename *smb_fname = NULL;
        NTSTATUS status;

        *_smb_fname = NULL;

        if (ucf_flags & UCF_DFS_PATHNAME) {
                char *fname = NULL;
                NTTIME dfs_twrp = 0;
                status = dfs_redirect(ctx, conn,
                                name_in,
                                ucf_flags,
                                !conn->sconn->using_smb2,
                                &dfs_twrp,
                                &fname);
                if (!NT_STATUS_IS_OK(status)) {
                        DBG_DEBUG("dfs_redirect "
                                "failed for name %s with %s\n",
                                name_in,
                                nt_errstr(status));
                        return status;
                }
                name_in = fname;
                ucf_flags &= ~UCF_DFS_PATHNAME;
                if (twrp == 0 && dfs_twrp != 0) {
                        twrp = dfs_twrp;
                }
        }

        if (is_fake_file_path(name_in)) {
                smb_fname = synthetic_smb_fname_split(ctx,
                                        name_in,
                                        (ucf_flags & UCF_POSIX_PATHNAMES));
                if (smb_fname == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }
                smb_fname->st = (SMB_STRUCT_STAT) { .st_ex_nlink = 1 };
                smb_fname->st.st_ex_btime = (struct timespec){0, SAMBA_UTIME_OMIT};
                smb_fname->st.st_ex_atime = (struct timespec){0, SAMBA_UTIME_OMIT};
                smb_fname->st.st_ex_mtime = (struct timespec){0, SAMBA_UTIME_OMIT};
                smb_fname->st.st_ex_ctime = (struct timespec){0, SAMBA_UTIME_OMIT};

                *_smb_fname = smb_fname;
                return NT_STATUS_OK;
        }

        status = unix_convert(ctx, conn, name_in, twrp, &smb_fname, ucf_flags);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("unix_convert failed "
                        "for name %s with %s\n",
                        name_in,
                        nt_errstr(status));
                return status;
        }

        if ((ucf_flags & UCF_POSIX_PATHNAMES) &&
            VALID_STAT(smb_fname->st) &&
            S_ISLNK(smb_fname->st.st_ex_mode))
        {
                status = check_veto_path(conn, smb_fname);
                if (!NT_STATUS_IS_OK(status)) {
                        TALLOC_FREE(smb_fname);
                        return status;
                }
        } else {
                status = check_name(conn, smb_fname);
        }
        if (!NT_STATUS_IS_OK(status)) {
                DBG_NOTICE("check_name failed "
                        "for name %s with %s\n",
                        smb_fname_str_dbg(smb_fname),
                        nt_errstr(status));
                TALLOC_FREE(smb_fname);
                return status;
        }

        if (!VALID_STAT(smb_fname->st)) {
                DBG_DEBUG("[%s] does not exist, skipping pathref fsp\n",
                          smb_fname_str_dbg(smb_fname));
                *_smb_fname = smb_fname;
                return NT_STATUS_OK;
        }

        status = openat_pathref_fsp(conn->cwd_fsp, smb_fname);
        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
                /*
                 * We deal with symlinks here as we do in
                 * SMB_VFS_CREATE_FILE(): return success for POSIX clients with
                 * the notable difference that there will be no fsp in
                 * smb_fname->fsp.
                 *
                 * For Windows (non POSIX) clients fail with
                 * NT_STATUS_OBJECT_NAME_NOT_FOUND.
                 */
                if (smb_fname->flags & SMB_FILENAME_POSIX_PATH &&
                    S_ISLNK(smb_fname->st.st_ex_mode))
                {
                        status = NT_STATUS_OK;
                }
        }
        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("openat_pathref_fsp [%s] failed: %s\n",
                          smb_fname_str_dbg(smb_fname),
                          nt_errstr(status));
                return status;
        }

        *_smb_fname = smb_fname;
        return status;
}

#if 0
/*
 * Strip a @GMT component from an SMB1-DFS path. Could be anywhere
 * in the path.
 */

static char *strip_gmt_from_raw_dfs(TALLOC_CTX *ctx,
                                    const char *name_in,
                                    bool posix_pathnames,
                                    NTTIME *_twrp)
{
        NTSTATUS status;
        struct smb_filename *smb_fname = NULL;
        char *name_out = NULL;

        smb_fname = synthetic_smb_fname(ctx,
                                        name_in,
                                        NULL,
                                        NULL,
                                        0,
                                        0);
        if (smb_fname == NULL) {
                return NULL;
        }
        if (!posix_pathnames) {
                /*
                 * Raw DFS names are still '\\' separated.
                 * canonicalize_snapshot_path() only works
                 * on '/' separated paths. Convert.
                 */
                string_replace(smb_fname->base_name, '\\', '/');
        }
        status = canonicalize_snapshot_path(smb_fname,
                                            UCF_GMT_PATHNAME,
                                            0);
        if (!NT_STATUS_IS_OK(status)) {
                TALLOC_FREE(smb_fname);
                return NULL;
        }
        if (!posix_pathnames) {
                /* Replace as raw DFS names. */
                string_replace(smb_fname->base_name, '/', '\\');
        }
        name_out = talloc_strdup(ctx, smb_fname->base_name);
        *_twrp = smb_fname->twrp;
        TALLOC_FREE(smb_fname);
        return name_out;
}
#endif

/*
 * Deal with the SMB1 semantics of sending a pathname with a
 * wildcard as the terminal component for a SMB1search or
 * trans2 findfirst.
 */

NTSTATUS filename_convert_smb1_search_path(TALLOC_CTX *ctx,
                                           connection_struct *conn,
                                           char *name_in,
                                           uint32_t ucf_flags,
                                           struct smb_filename **_smb_fname_out,
                                           char **_mask_out)
{
        NTSTATUS status;
        char *p = NULL;
        char *mask = NULL;
        struct smb_filename *smb_fname = NULL;
        bool posix_pathnames = (ucf_flags & UCF_POSIX_PATHNAMES);
        NTTIME twrp = 0;

        *_smb_fname_out = NULL;
        *_mask_out = NULL;

        DBG_DEBUG("name_in: %s\n", name_in);

        if (ucf_flags & UCF_GMT_PATHNAME) {
                extract_snapshot_token(name_in, ucf_flags, &twrp);
                ucf_flags &= ~UCF_GMT_PATHNAME;
        }

        if (ucf_flags & UCF_DFS_PATHNAME) {
                /*
                 * We've been given a raw DFS pathname.
                 * In Windows mode this is separated by '\'
                 * characters, in POSIX by '/' characters.
                 */
                char path_sep = posix_pathnames ? '/' : '\\';
                char *fname = NULL;
                char *name_in_copy = NULL;
                char *last_component = NULL;

                /* Work on a copy of name_in. */
                name_in_copy = talloc_strdup(ctx, name_in);
                if (name_in_copy == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }

                /*
                 * Now we know that the last component is the
                 * wildcard. Copy it and truncate to remove it.
                 */
                p = strrchr_m(name_in_copy, path_sep);
                if (p == NULL) {
                        last_component = talloc_strdup(ctx, name_in_copy);
                        name_in_copy[0] = '\0';
                } else {
                        last_component = talloc_strdup(ctx, p+1);
                        *p = '\0';
                }
                if (last_component == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }

                DBG_DEBUG("name_in_copy: %s\n", name_in_copy);

                /*
                 * Now we can call dfs_redirect()
                 * on the name without wildcard.
                 */
                status = dfs_redirect(ctx,
                                      conn,
                                      name_in_copy,
                                      ucf_flags,
                                      !conn->sconn->using_smb2,
                                      NULL,
                                      &fname);
                if (!NT_STATUS_IS_OK(status)) {
                        DBG_DEBUG("dfs_redirect "
                                "failed for name %s with %s\n",
                                name_in_copy,
                                nt_errstr(status));
                        return status;
                }
                /* Add the last component back. */
                if (fname[0] == '\0') {
                        name_in = talloc_strdup(ctx, last_component);
                } else {
                        name_in = talloc_asprintf(ctx,
                                                  "%s%c%s",
                                                  fname,
                                                  path_sep,
                                                  last_component);
                }
                if (name_in == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }
                ucf_flags &= ~UCF_DFS_PATHNAME;

                DBG_DEBUG("After DFS redirect name_in: %s\n", name_in);
        }

        smb_fname = synthetic_smb_fname(ctx,
                                        name_in,
                                        NULL,
                                        NULL,
                                        twrp,
                                        posix_pathnames ?
                                                SMB_FILENAME_POSIX_PATH : 0);
        if (smb_fname == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        /* Get the original lcomp. */
        mask = get_original_lcomp(ctx,
                                  conn,
                                  name_in,
                                  ucf_flags);
        if (mask == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        if (mask[0] == '\0') {
                /* Windows and OS/2 systems treat search on the root as * */
                TALLOC_FREE(mask);
                mask = talloc_strdup(ctx, "*");
                if (mask == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }
        }

        DBG_DEBUG("mask = %s\n", mask);

        /*
         * Remove the terminal component so
         * filename_convert never sees the mask.
         */
        p = strrchr_m(smb_fname->base_name,'/');
        if (p == NULL) {
                /* filename_convert handles a '\0' base_name. */
                smb_fname->base_name[0] = '\0';
        } else {
                *p = '\0';
        }

        DBG_DEBUG("For filename_convert: smb_fname = %s\n",
                smb_fname_str_dbg(smb_fname));

        /* Convert the parent directory path. */
        status = filename_convert(ctx,
                                  conn,
                                  smb_fname->base_name,
                                  ucf_flags,
                                  smb_fname->twrp,
                                  &smb_fname);

        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("filename_convert error for %s: %s\n",
                        smb_fname_str_dbg(smb_fname),
                        nt_errstr(status));
        }

        *_smb_fname_out = talloc_move(ctx, &smb_fname);
        *_mask_out = talloc_move(ctx, &mask);

        return status;
}

/*
 * Get the correct capitalized stream name hanging off
 * base_fsp. Equivalent of get_real_filename(), but for streams.
 */
static NTSTATUS get_real_stream_name(
        TALLOC_CTX *mem_ctx,
        struct files_struct *base_fsp,
        const char *stream_name,
        char **_found)
{
        unsigned int i, num_streams = 0;
        struct stream_struct *streams = NULL;
        NTSTATUS status;

        status = vfs_fstreaminfo(
                base_fsp, talloc_tos(), &num_streams, &streams);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        for (i=0; i<num_streams; i++) {
                bool equal = sname_equal(stream_name, streams[i].name, false);

                DBG_DEBUG("comparing [%s] and [%s]: %sequal\n",
                          stream_name,
                          streams[i].name,
                          equal ? "" : "not ");

                if (equal) {
                        *_found = talloc_move(mem_ctx, &streams[i].name);
                        TALLOC_FREE(streams);
                        return NT_STATUS_OK;
                }
        }

        TALLOC_FREE(streams);
        return NT_STATUS_OBJECT_NAME_NOT_FOUND;
}

static bool filename_split_lcomp(
        TALLOC_CTX *mem_ctx,
        const char *name_in,
        bool posix,
        char **_dirname,
        const char **_fname_rel,
        const char **_streamname)
{
        const char *lcomp = NULL;
        const char *fname_rel = NULL;
        const char *streamname = NULL;
        char *dirname = NULL;

        if (name_in[0] == '\0') {
                fname_rel = ".";
                dirname = talloc_strdup(mem_ctx, "");
                if (dirname == NULL) {
                        return false;
                }
                goto done;
        }

        lcomp = strrchr_m(name_in, '/');
        if (lcomp != NULL) {
                fname_rel = lcomp+1;
                dirname = talloc_strndup(mem_ctx, name_in, lcomp - name_in);
                if (dirname == NULL) {
                        return false;
                }
                goto find_stream;
        }

        /*
         * No slash, dir is emtpy
         */
        dirname = talloc_strdup(mem_ctx, "");
        if (dirname == NULL) {
                return false;
        }

        if (!posix && (name_in[0] == ':')) {
                /*
                 * Special case for stream on root directory
                 */
                fname_rel = ".";
                streamname = name_in;
                goto done;
        }

        fname_rel = name_in;

find_stream:
        if (!posix) {
                streamname = strchr_m(fname_rel, ':');

                if (streamname != NULL) {
                        fname_rel = talloc_strndup(
                                mem_ctx,
                                fname_rel,
                                streamname - fname_rel);
                        if (fname_rel == NULL) {
                                TALLOC_FREE(dirname);
                                return false;
                        }
                }
        }

done:
        *_dirname = dirname;
        *_fname_rel = fname_rel;
        *_streamname = streamname;
        return true;
}

/*
 * Create the correct capitalization of a file name to be created.
 */
static NTSTATUS filename_convert_normalize_new(
        TALLOC_CTX *mem_ctx,
        struct connection_struct *conn,
        char *name_in,
        char **_normalized)
{
        char *name = name_in;

        *_normalized = NULL;

        if (!conn->case_preserve ||
            (mangle_is_8_3(name, false,
                           conn->params) &&
             !conn->short_case_preserve)) {

                char *normalized = talloc_strdup(mem_ctx, name);
                if (normalized == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }

                strnorm(normalized, lp_default_case(SNUM(conn)));
                name = normalized;
        }

        if (mangle_is_mangled(name, conn->params)) {
                bool found;
                char *unmangled = NULL;

                found = mangle_lookup_name_from_8_3(
                        mem_ctx, name, &unmangled, conn->params);
                if (found) {
                        name = unmangled;
                }
        }

        if (name != name_in) {
                *_normalized = name;
        }

        return NT_STATUS_OK;
}

/*
 * Open smb_fname_rel->fsp as a pathref fsp with a case insensitive
 * fallback using GETREALFILENAME_CACHE and get_real_filename_at() if
 * the first attempt based on the filename sent by the client gives
 * ENOENT.
 */
static NTSTATUS openat_pathref_fsp_case_insensitive(
        struct files_struct *dirfsp,
        struct smb_filename *smb_fname_rel,
        uint32_t ucf_flags)
{
        const bool posix = (ucf_flags & UCF_POSIX_PATHNAMES);
        DATA_BLOB cache_key = { .data = NULL, };
        char *found_name = NULL;
        NTSTATUS status;
        bool ok;

        SET_STAT_INVALID(smb_fname_rel->st);

        status = openat_pathref_fsp(dirfsp, smb_fname_rel);

        if (NT_STATUS_IS_OK(status)) {
                return NT_STATUS_OK;
        }

        if (VALID_STAT(smb_fname_rel->st)) {
                /*
                 * We got an error although the object existed. Might
                 * be a symlink we don't want.
                 */
                return status;
        }

        if (!NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
                /*
                 * Only retry on ENOENT
                 */
                return status;
        }

        if (posix || dirfsp->conn->case_sensitive) {
                /*
                 * Only return case insensitive if required
                 */
                return status;
        }

        if (lp_stat_cache()) {
                char *base_name = smb_fname_rel->base_name;
                DATA_BLOB value = { .data = NULL };

                ok = get_real_filename_cache_key(
                        talloc_tos(), dirfsp, base_name, &cache_key);
                if (!ok) {
                        /*
                         * probably ENOMEM, just bail
                         */
                        return status;
                }

                DO_PROFILE_INC(statcache_lookups);

                ok = memcache_lookup(
                        NULL, GETREALFILENAME_CACHE, cache_key, &value);
                if (!ok) {
                        DO_PROFILE_INC(statcache_misses);
                        goto lookup;
                }
                DO_PROFILE_INC(statcache_hits);

                TALLOC_FREE(smb_fname_rel->base_name);
                smb_fname_rel->base_name = talloc_memdup(
                        smb_fname_rel, value.data, value.length);
                if (smb_fname_rel->base_name == NULL) {
                        TALLOC_FREE(cache_key.data);
                        return NT_STATUS_NO_MEMORY;
                }

                status = openat_pathref_fsp(dirfsp, smb_fname_rel);
                if (NT_STATUS_IS_OK(status)) {
                        TALLOC_FREE(cache_key.data);
                        return NT_STATUS_OK;
                }

                memcache_delete(NULL, GETREALFILENAME_CACHE, cache_key);
        }

lookup:
        status = get_real_filename_at(
                dirfsp, smb_fname_rel->base_name, smb_fname_rel, &found_name);
        if (NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED) &&
            (ucf_flags & UCF_PREP_CREATEFILE)) {
                /*
                 * dropbox
                 */
                status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
        }

        if (NT_STATUS_IS_OK(status)) {
                TALLOC_FREE(smb_fname_rel->base_name);
                smb_fname_rel->base_name = found_name;

                status = openat_pathref_fsp(dirfsp, smb_fname_rel);
        }

        if (NT_STATUS_IS_OK(status) && (cache_key.data != NULL)) {
                DATA_BLOB value = {
                        .data = (uint8_t *)smb_fname_rel->base_name,
                        .length = strlen(smb_fname_rel->base_name) + 1,
                };

                memcache_add(NULL, GETREALFILENAME_CACHE, cache_key, value);
        }

        TALLOC_FREE(cache_key.data);

        return status;
}

/*
 * Split up name_in as sent by the client into a directory pathref fsp
 * and a relative smb_filename.
 */
static const char *previous_slash(const char *name_in, const char *slash)
{
        const char *prev = name_in;

        while (true) {
                const char *next = strchr_m(prev, '/');

                SMB_ASSERT(next != NULL); /* we have at least one slash */

                if (next == slash) {
                        break;
                }

                prev = next+1;
        };

        if (prev == name_in) {
                /* no previous slash */
                return NULL;
        }

        return prev;
}

static char *symlink_target_path(
        TALLOC_CTX *mem_ctx,
        const char *name_in,
        const char *substitute,
        size_t unparsed)
{
        size_t name_in_len = strlen(name_in);
        const char *p_unparsed = NULL;
        const char *parent = NULL;
        char *ret;

        SMB_ASSERT(unparsed <= name_in_len);

        p_unparsed = name_in + (name_in_len - unparsed);

        if (substitute[0] == '/') {
                ret = talloc_asprintf(mem_ctx, "%s%s", substitute, p_unparsed);
                return ret;
        }

        if (unparsed == 0) {
                parent = strrchr_m(name_in, '/');
        } else {
                parent = previous_slash(name_in, p_unparsed);
        }

        if (parent == NULL) {
                /* no previous slash */
                parent = name_in;
        }

        ret = talloc_asprintf(
                mem_ctx,
                "%.*s%s%s",
                (int)(parent - name_in),
                name_in,
                substitute,
                p_unparsed);
        return ret;
}

/*
 * Split up name_in as sent by the client into a directory pathref fsp
 * and a relative smb_filename.
 */
static NTSTATUS filename_convert_dirfsp_nosymlink(
        TALLOC_CTX *mem_ctx,
        connection_struct *conn,
        const char *name_in,
        uint32_t ucf_flags,
        NTTIME twrp,
        struct files_struct **_dirfsp,
        struct smb_filename **_smb_fname,
        char **_substitute,
        size_t *_unparsed)
{
        struct smb_filename *smb_dirname = NULL;
        struct smb_filename *smb_fname_rel = NULL;
        struct smb_filename *smb_fname = NULL;
        const bool posix = (ucf_flags & UCF_POSIX_PATHNAMES);
        char *dirname = NULL;
        const char *fname_rel = NULL;
        const char *streamname = NULL;
        char *saved_streamname = NULL;
        struct files_struct *base_fsp = NULL;
        bool ok;
        NTSTATUS status = NT_STATUS_UNSUCCESSFUL;

        if (ucf_flags & UCF_DFS_PATHNAME) {
                char *fname = NULL;
                NTTIME dfs_twrp = 0;
                status = dfs_redirect(
                        mem_ctx,
                        conn,
                        name_in,
                        ucf_flags,
                        !conn->sconn->using_smb2,
                        &dfs_twrp,
                        &fname);
                if (!NT_STATUS_IS_OK(status)) {
                        DBG_DEBUG("dfs_redirect "
                                "failed for name %s with %s\n",
                                name_in,
                                nt_errstr(status));
                        return status;
                }
                name_in = fname;
                ucf_flags &= ~UCF_DFS_PATHNAME;
                if (twrp == 0 && dfs_twrp != 0) {
                        twrp = dfs_twrp;
                }
        }

        if (is_fake_file_path(name_in) || conn->printer) {
                smb_fname = synthetic_smb_fname_split(mem_ctx, name_in, posix);
                if (smb_fname == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }
                smb_fname->st = (SMB_STRUCT_STAT) { .st_ex_nlink = 1 };
                smb_fname->st.st_ex_btime =
                        (struct timespec){0, SAMBA_UTIME_OMIT};
                smb_fname->st.st_ex_atime =
                        (struct timespec){0, SAMBA_UTIME_OMIT};
                smb_fname->st.st_ex_mtime =
                        (struct timespec){0, SAMBA_UTIME_OMIT};
                smb_fname->st.st_ex_ctime =
                        (struct timespec){0, SAMBA_UTIME_OMIT};

                *_dirfsp = conn->cwd_fsp;
                *_smb_fname = smb_fname;
                return NT_STATUS_OK;
        }

        /*
         * Catch an invalid path of "." before we
         * call filename_split_lcomp(). We need to
         * do this as filename_split_lcomp() will
         * use "." for the missing relative component
         * when an empty name_in path is sent by
         * the client.
         */
        if (ISDOT(name_in)) {
                status = NT_STATUS_OBJECT_NAME_INVALID;
                goto fail;
        }

        ok = filename_split_lcomp(
                talloc_tos(),
                name_in,
                posix,
                &dirname,
                &fname_rel,
                &streamname);
        if (!ok) {
                status = NT_STATUS_NO_MEMORY;
                goto fail;
        }

        if (!posix) {
                bool name_has_wild = ms_has_wild(dirname);
                name_has_wild |= ms_has_wild(fname_rel);
                if (name_has_wild) {
                        status = NT_STATUS_OBJECT_NAME_INVALID;
                        goto fail;
                }
        }

        if (dirname[0] == '\0') {
                status = synthetic_pathref(
                        mem_ctx,
                        conn->cwd_fsp,
                        ".",
                        NULL,
                        NULL,
                        0,
                        posix ? SMB_FILENAME_POSIX_PATH : 0,
                        &smb_dirname);
        } else {
                char *substitute = NULL;
                size_t unparsed = 0;

                status = openat_pathref_dirfsp_nosymlink(
                        mem_ctx,
                        conn,
                        dirname,
                        0,
                        &smb_dirname,
                        &unparsed,
                        &substitute);

                if (NT_STATUS_EQUAL(status, NT_STATUS_STOPPED_ON_SYMLINK)) {

                        size_t name_in_len = strlen(name_in);
                        size_t dirname_len = strlen(dirname);

                        SMB_ASSERT(name_in_len >= dirname_len);

                        *_substitute = substitute;
                        *_unparsed = unparsed + (name_in_len - dirname_len);

                        goto fail;
                }
        }

        if (!NT_STATUS_IS_OK(status)) {
                DBG_DEBUG("opening directory %s failed: %s\n",
                          dirname,
                          nt_errstr(status));
                TALLOC_FREE(dirname);

                if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
                        /*
                         * Except ACCESS_DENIED, everything else leads
                         * to PATH_NOT_FOUND.
                         */
                        status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                }

                goto fail;
        }

        if (!VALID_STAT_OF_DIR(smb_dirname->st)) {
                status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
                goto fail;
        }

        /*
         * Only look at bad last component values
         * once we know we have a valid directory. That
         * way we won't confuse error messages from
         * opening the directory path with error
         * messages from a bad last component.
         */

        /* Relative filename can't be empty */
        if (fname_rel[0] == '\0') {
                status = NT_STATUS_OBJECT_NAME_INVALID;
                goto fail;
        }

        /* Relative filename can't be ".." */
        if (ISDOTDOT(fname_rel)) {
                status = NT_STATUS_OBJECT_NAME_INVALID;
                goto fail;
        }
        /* Relative name can only be dot if directory is empty. */
        if (ISDOT(fname_rel) && dirname[0] != '\0') {
                status = NT_STATUS_OBJECT_NAME_INVALID;
                goto fail;
        }

        TALLOC_FREE(dirname);

        smb_fname_rel = synthetic_smb_fname(
                mem_ctx,
                fname_rel,
                streamname,
                NULL,
                twrp,
                posix ? SMB_FILENAME_POSIX_PATH : 0);
        if (smb_fname_rel == NULL) {
                status = NT_STATUS_NO_MEMORY;
                goto fail;
        }

        if ((conn->fs_capabilities & FILE_NAMED_STREAMS) &&
            is_named_stream(smb_fname_rel)) {
                /*
                 * Find the base_fsp first without the stream.
                 */
                saved_streamname = smb_fname_rel->stream_name;
                smb_fname_rel->stream_name = NULL;
        }

        status = normalize_filename_case(
                conn, smb_fname_rel->base_name, ucf_flags);
        if (!NT_STATUS_IS_OK(status)) {
                DBG_ERR("normalize_filename_case %s failed: %s\n",
                        smb_fname_rel->base_name,
                        nt_errstr(status));
                goto fail;
        }

        status = openat_pathref_fsp_case_insensitive(
                smb_dirname->fsp, smb_fname_rel, ucf_flags);

        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {

                char *normalized = NULL;

                if (VALID_STAT(smb_fname_rel->st)) {
#if defined(WITH_SMB1SERVER)
                        /*
                         * In SMB1 posix mode, if this is a symlink,
                         * allow access to the name with a NULL smb_fname->fsp.
                         */
                        if (!conn->sconn->using_smb2 &&
                                        posix &&
                                        S_ISLNK(smb_fname_rel->st.st_ex_mode)) {
                                SMB_ASSERT(smb_fname_rel->fsp == NULL);
                                SMB_ASSERT(streamname == NULL);

                                smb_fname = full_path_from_dirfsp_atname(
                                                mem_ctx,
                                                smb_dirname->fsp,
                                                smb_fname_rel);
                                if (smb_fname == NULL) {
                                        status = NT_STATUS_NO_MEMORY;
                                        goto fail;
                                }
                                goto done;
                        }
#endif
                        /*
                         * NT_STATUS_OBJECT_NAME_NOT_FOUND is
                         * misleading: The object exists but might be
                         * a symlink pointing outside the share.
                         */
                        goto fail;
                }

                /*
                 * Creating a new file
                 */

                status = filename_convert_normalize_new(
                        smb_fname_rel,
                        conn,
                        smb_fname_rel->base_name,
                        &normalized);
                if (!NT_STATUS_IS_OK(status)) {
                        DBG_DEBUG("filename_convert_normalize_new failed: "
                                  "%s\n",
                                  nt_errstr(status));
                        goto fail;
                }
                if (normalized != NULL) {
                        smb_fname_rel->base_name = normalized;
                }

                smb_fname_rel->stream_name = saved_streamname;

                smb_fname = full_path_from_dirfsp_atname(
                        mem_ctx, smb_dirname->fsp, smb_fname_rel);
                if (smb_fname == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto fail;
                }
                goto done;
        }

        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }

        if (saved_streamname == NULL) {
                /* smb_fname must be allocated off mem_ctx. */
                smb_fname = cp_smb_filename(mem_ctx,
                                            smb_fname_rel->fsp->fsp_name);
                if (smb_fname == NULL) {
                        goto fail;
                }
                status = move_smb_fname_fsp_link(smb_fname, smb_fname_rel);
                if (!NT_STATUS_IS_OK(status)) {
                        goto fail;
                }
                goto done;
        }

        base_fsp = smb_fname_rel->fsp;
        smb_fname_fsp_unlink(smb_fname_rel);
        SET_STAT_INVALID(smb_fname_rel->st);

        smb_fname_rel->stream_name = saved_streamname;

        status = open_stream_pathref_fsp(&base_fsp, smb_fname_rel);

        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND) &&
            !conn->case_sensitive) {
                char *found = NULL;

                status = get_real_stream_name(
                        smb_fname_rel,
                        base_fsp,
                        smb_fname_rel->stream_name,
                        &found);

                if (NT_STATUS_IS_OK(status)) {
                        smb_fname_rel->stream_name = found;
                        found = NULL;
                        status = open_stream_pathref_fsp(
                                &base_fsp, smb_fname_rel);
                }
        }

        if (NT_STATUS_IS_OK(status)) {
                /* smb_fname must be allocated off mem_ctx. */
                smb_fname = cp_smb_filename(mem_ctx,
                                            smb_fname_rel->fsp->fsp_name);
                if (smb_fname == NULL) {
                        goto fail;
                }
                status = move_smb_fname_fsp_link(smb_fname, smb_fname_rel);
                if (!NT_STATUS_IS_OK(status)) {
                        goto fail;
                }
                goto done;
        }

        if (NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_NAME_NOT_FOUND)) {
                /*
                 * Creating a new stream
                 *
                 * We should save the already-open base fsp for
                 * create_file_unixpath() somehow.
                 */
                smb_fname = full_path_from_dirfsp_atname(
                        mem_ctx, smb_dirname->fsp, smb_fname_rel);
                if (smb_fname == NULL) {
                        status = NT_STATUS_NO_MEMORY;
                        goto fail;
                }
                goto done;
        }

        if (!NT_STATUS_IS_OK(status)) {
                goto fail;
        }

done:
        *_dirfsp = smb_dirname->fsp;
        *_smb_fname = smb_fname;

        smb_fname_fsp_unlink(smb_fname_rel);
        TALLOC_FREE(smb_fname_rel);
        return NT_STATUS_OK;

fail:
        TALLOC_FREE(dirname);
        TALLOC_FREE(smb_dirname);
        TALLOC_FREE(smb_fname_rel);
        return status;
}

NTSTATUS filename_convert_dirfsp(
        TALLOC_CTX *mem_ctx,
        connection_struct *conn,
        const char *name_in,
        uint32_t ucf_flags,
        NTTIME twrp,
        struct files_struct **_dirfsp,
        struct smb_filename **_smb_fname)
{
        char *substitute = NULL;
        size_t unparsed = 0;
        NTSTATUS status;
        char *target = NULL;
        char *abs_target = NULL;
        char *abs_target_canon = NULL;
        size_t symlink_redirects = 0;
        bool in_share;

next:
        if (symlink_redirects > 40) {
                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
        }

        status = filename_convert_dirfsp_nosymlink(
                mem_ctx,
                conn,
                name_in,
                ucf_flags,
                twrp,
                _dirfsp,
                _smb_fname,
                &substitute,
                &unparsed);

#if defined(WITH_SMB1SERVER)
        /*
         * This isn't 100% correct, but it gets us close enough
         * to the old behavior for SMB1+POSIX libsmbclient. If we went through a
         * symlink, and we got NT_STATUS_ACCESS_DENIED on the directory
         * containing the target, just don't allow the client to see the
         * intermediate path.
         */
        if (!conn->sconn->using_smb2 &&
                        (ucf_flags & UCF_POSIX_PATHNAMES) &&
                        symlink_redirects > 0 &&
                        NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
        }
#endif

        if (!NT_STATUS_EQUAL(status, NT_STATUS_STOPPED_ON_SYMLINK)) {
                return status;
        }

        if (!lp_follow_symlinks(SNUM(conn))) {
                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
        }

        /*
         * Right now, SMB2 and SMB1 always traverse symlinks
         * within the share. SMB1+POSIX traverses non-terminal
         * symlinks within the share.
         *
         * When we add SMB2+POSIX we need to return
         * a NT_STATUS_STOPPED_ON_SYMLINK error here, using the
         * symlink target data read below if SMB2+POSIX has
         * UCF_POSIX_PATHNAMES set to cause the client to
         * resolve all symlinks locally.
         */

        target = symlink_target_path(mem_ctx, name_in, substitute, unparsed);
        if (target == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        DBG_DEBUG("name_in: %s, substitute: %s, unparsed: %zu, target=%s\n",
                  name_in,
                  substitute,
                  unparsed,
                  target);

        if (target[0] == '/') {
                abs_target = target;
        } else {
                abs_target = talloc_asprintf(
                        mem_ctx, "%s/%s", conn->connectpath, target);
                if (abs_target == NULL) {
                        return NT_STATUS_NO_MEMORY;
                }
        }

        abs_target_canon = canonicalize_absolute_path(mem_ctx, abs_target);
        if (abs_target_canon == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        DBG_DEBUG("abs_target_canon=%s\n", abs_target_canon);

        in_share = strncmp(
                abs_target_canon,
                conn->connectpath,
                strlen(conn->connectpath)) == 0;
        if (!in_share) {
                DBG_DEBUG("wide link to %s\n", abs_target_canon);
                return NT_STATUS_OBJECT_PATH_NOT_FOUND;
        }

        name_in = talloc_strdup(
                mem_ctx, abs_target_canon + strlen(conn->connectpath) + 1);

        symlink_redirects += 1;

        goto next;
}

/*
 * Build the full path from a dirfsp and dirfsp relative name
 */
struct smb_filename *full_path_from_dirfsp_atname(
        TALLOC_CTX *mem_ctx,
        const struct files_struct *dirfsp,
        const struct smb_filename *atname)
{
        struct smb_filename *fname = NULL;
        char *path = NULL;

        if (dirfsp == dirfsp->conn->cwd_fsp ||
            ISDOT(dirfsp->fsp_name->base_name) ||
            atname->base_name[0] == '/')
        {
                path = talloc_strdup(mem_ctx, atname->base_name);
        } else {
                path = talloc_asprintf(mem_ctx, "%s/%s",
                                       dirfsp->fsp_name->base_name,
                                       atname->base_name);
        }
        if (path == NULL) {
                return NULL;
        }

        fname = synthetic_smb_fname(mem_ctx,
                                    path,
                                    atname->stream_name,
                                    &atname->st,
                                    atname->twrp,
                                    atname->flags);
        TALLOC_FREE(path);
        if (fname == NULL) {
                return NULL;
        }

        return fname;
}